1. Field of the Invention
The present invention pertains to the construction of rollers of the runner or roller guide for a sliding elevator door, which includes resilient members for achieving greater quietness of operation.
2. Discussion of the Background of the Invention and Material Information
A roller guide for a sliding elevator door, in which the rollers include elastic inserts for the improvement of the quietness of operation is set forth in European Patent Publication EP 478 938 and cognate U.S. Pat. No. 5,165,142. These inserts consist of non-metallic, hard, elastic material. In order to avoid flat spotting of the elastic inserts, the running surfaces are relieved or unloaded in the standstill or at rest positions. This unloading occurs through roller-raising or lifting devices that are mounted laterally of the guide rail and are constructed as ramp members with a ramp and a horizontal part. The rim disks of the rollers enable a run-up onto the ramp members and a relief of the running surfaces.
In the case of a worn elastic insert, the entire roller must be replaced in this mode of construction. The softer the nature of the running surface, the better the quietness of operation, however the greater the wear of the insert. Production thereof is made more expensive due to the expense of producing the shape of the roller and the mounting of the elastic insert. Beyond that, due to the use of soft running surface inserts, the embedding of foreign materials is also made possible and impairs the quiet running thereof.
It is the task or object of this invention to construct a roller guide for a sliding elevator door of the type previously described which does not include the disadvantages thereof and which assures a high degree of quiet running in a simple manner.